No-one likes traffic lights. Whether you are a driver or a pedestrian, a traffic light on red is seen as a restriction on your mobility.

And they always seem to take far longer to change than is really necessary. So, Martin Cassini has an easy target.

However, we do need to be very careful not to jeopardise safety because we feel our freedoms are being constrained.

Sometimes, we have to go beyond our personal and individual prejudices to think of the greater good.

Road use is an immensely complicated task undertaken in a highly communal space. The decisions that I take can have far-reaching consequences for your safety or for your level of risk.

Two contentions

Mr Cassini appears to base his arguments on two main contentions.

First, if we removed external controls on them, all drivers would behave in a more responsible and adult way.

Second, in those places where this approach has been tried, the number of collisions and injuries has fallen.

The difficulty with the first premise is that it requires us to take a leap of faith. We have to hope that this will be the case rather than have any guarantee that it will be so.

In the examples that he shows in his film, traffic is moving fairly slowly on already congested urban roads. However, we have to apply the principles universally.

Would such an approach succeed on faster flowing routes out of towns where the speed limit is currently higher? If we created an environment without some form of control, would those drivers who currently violate existing law by breaking the speed limit and running red lights, thereby placing us all at risk, decide to comply voluntarily?

I have my doubts.

Robert Gifford argues for better enforcement rather than a ban

Furthermore, to answer his second point, the evidence from the real world on reduced collisions is very mixed. The concept of "shared space" has been tried in a number of places in the Netherlands.

However, all of the towns are relatively small compared to London, traffic flows are low, and the number of damage-only collisions remained pretty unchanged.

The concept has not been tried at junctions or on roads with a history of deaths - exactly the context where in Great Britain we would consider a light-controlled signal to help the pedestrian as a vulnerable road user.

More cooperation

I entirely agree that we need a more cooperative approach to road use. The Department for Transport "Think" campaign has tried to do precisely that. In terms of equity on our roads, we need to do far more to protect the vulnerable - pedestrians, children and cyclists.

Giving power to the car driver to decide when and when not to stop does little to rectify the power relationships on our roads. Better enforcement of current law would be far more effective.

Our key difficulty is that the bulk of our transport network was designed in the 18th and 19th Centuries. It is now dealing with 21st Century challenges. Designing from scratch - as in Thames Gateway - could offer us an opportunity to try out "shared space".

On most of our roads, however, more lives would be lost if we moved in that direction.

Robert Gifford is the Executive Director of the Parliamentary Advisory Council for Transport Safety.